Trace gas emissions from a sun and shade grown ornamental crop

Authors: MURPHY, ANNA-MARIE - Auburn University; Prior, Stephen - Steve; Runion, George; Torbert, Henry - Allen; SIBLEY, JEFF - Auburn University

Submitted to: Southern Region of the American Society for Horticultural Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/4/2018
Publication Date: 2/4/2018
Citation: Murphy, A., Prior, S.A., Runion, G.B., Torbert III, H.A., Sibley, J.L. 2018. Trace gas emissions from a sun and shade grown ornamental crop [abstract]. HortScience. 53(9):S483.

Interpretive Summary:

Technical Abstract: Previous work has begun to establish baseline approximations for greenhouse gas (GHG) (CO2, CH4, and N2O) emissions of several horticultural crops, though much work is still needed to expand contingencies for multiple best management practices. In this study, GHG emissions from one shade-grown species, ‘Royal Standard’ hosta (Hosta ‘Royal Standard’), and one sun-grown species, ‘Stella D’Oro’ daylily (Hemerocallis ‘Stella D’Oro’), were evaluated in standard bark-based substrates with one of three fertilizer methods (dibbling, incorporated, or top-dressed) (25 g per container of Polyon 16-5-10, 12-month release + micros). Plants were grown in 3.5 L (1 gal) nursery containers, and irrigated with overhead irrigation calibrated to deliver 6.35 mm (0.25 in) water three times daily. Gas samples were collected in situ once weekly over a 5-month period (23 April to 24 Sept, 2015) using the static closed chamber method according to standard protocols and analyzed using gas chromatography. Both CO2 and N2O total cumulative efflux was least for plants fertilized with the dibbled method, regardless of species. Total cumulative CO2 emissions were greatest for both daylily and hosta with incorporated fertilizer, though in the case of the sun-grown daylily, CO2 efflux was similar among plants with fertilizer that had been either incorporated or top-dressed. There were no differences in N2O efflux for both the incorporated and top-dressed treatments of shade-grown hostas and sun-grown daylilys. Methane (CH4) efflux was consistently low throughout the study. Commensurate with previous work, daily CO2 and N2O emissions experienced a spike at study initiation. In general, daily CO2 efflux was greater for shade-grown hosta than for daylily, while initial spikes in daily N2O emissions were greater for sun-grown daylily than for shade-grown hosta. Findings suggest that utilizing a dibbled fertilizer placement could significantly decrease both CO2 and N2O emission.